AUDIO: Fix CMS chips incorrect pitch.

The CMS emulation assumes the chips run at 8 MHz clock,
but in PCs they run at 7.15909 MHz, so the emulated pitch
is too high. Adjusting the requested sampling rate higher
by matching amount the pitch is lowered down to normal.

1 files changed, 3 insertions, 1 deletions

diff --git a/audio/softsynth/cms.h b/audio/softsynth/cms.h
index 8c0f980b0a..64df30e037 100644
--- a/audio/softsynth/cms.h
+++ b/audio/softsynth/cms.h
@@ -68,7 +68,9 @@ struct SAA1099 {
 class CMSEmulator {
 public:
 	CMSEmulator(uint32 sampleRate) {
-		_sampleRate = sampleRate;
+		// In PCs the chips run at 7.15909 MHz instead of 8 MHz.
+		// Adjust sampling rate upwards to bring pitch down.
+		_sampleRate = (sampleRate * 352) / 315;
 		memset(_saa1099, 0, sizeof(SAA1099)*2);
 	}